Our advantage
Global Logistics
We have a 10-year logistics and express cooperation agreement, so our products can be shipped to any place in the world.
Brand new and original
Our products are imported in bulk from the place of origin. Because of the cooperative relationship, our products are all original and 100% new.
24-hour service
We provide 7*24 hours service to our customers. We will be there whenever you need us.
Price advantage
All our products are priced very favorably because we have our own warehouse and supply.
| Company Information | |||
| sales@plc-automations.com | |||
| Mobile | +8615980777398 | ||
| +8615980777398 | |||
| 15980777398 |

The Yokogawa EC402-51 is an advanced ESB (Enhanced System Bus) Bus Coupler Module designed for use within distributed control systems (DCS). It acts as a critical communication bridge between the Field Control Unit (FCU) and Node Units, facilitating reliable and high-speed data transmission across a network. This module supports up to 13 node units per FCU and operates with a communication speed of 128 Mbps, making it ideal for complex industrial automation environments requiring robust, scalable, and redundant communication networks.
Brand: Yokogawa
Series: EC Series — ESB Bus Coupler Modules
Industrial Process Control (Oil & Gas, Chemical, Power Generation)
Distributed Control Systems requiring high-speed bus communications
Systems requiring multiple node connectivity per FCU
Redundant communication network architectures
Harsh industrial environments needing durable, reliable modules
High Node Capacity: Supports up to 13 nodes per FCU, expanding system scalability.
Fast Communication: Operates at 128 Mbps ensuring low latency and fast data transfer.
Redundancy Ready: Enables network redundancy for enhanced system reliability.
Compact & Lightweight: Small footprint allowing easy integration into control cabinets.
Robust Diagnostics: Includes status LEDs for real-time monitoring and fault detection.
Wide Operating Conditions: Functions reliably over a wide temperature and humidity range.
| Parameter | Specification |
|---|---|
| Model | EC402-51 |
| Function | ESB Bus Coupler Module (FCU to Node Units) |
| Max Node Units Supported | 13 nodes |
| Communication Speed | 128 Mbps |
| Power Supply | 24 V DC (via system backplane) |
| Operating Temperature | –10 °C to +55 °C |
| Storage Temperature | –40 °C to +85 °C |
| Relative Humidity | 5 % to 95 % (non-condensing) |
| Dimensions (W × H × D) | 130 × 129.5 × 32.8 mm |
| Weight | 0.24 kg |
| Communication Interface | Dual ESB ports |
| Diagnostic Features | Status and fault LEDs |
| Model | Description | Dimensions (mm) | Weight (kg) |
|---|---|---|---|
| EC402-50 | Basic ESB Bus Coupler supporting fewer nodes | 130 × 129.5 × 32.8 | 0.24 |
| EC402-51 | (This product) Advanced with 13 node support | 130 × 129.5 × 32.8 | 0.24 |
| EC402-50 S1 | Redundancy-enabled model with dual bus ports | Same as EC402-50 | ~1.0 |
| EC401-50 | Earlier single-port coupler, less capacity | Similar | ~0.3 |
| ANB10D | Combined Node and Bus interface unit | Larger module | ~0.5 |
| Model | Functionality | Dimensions (mm) | Weight (kg) |
|---|---|---|---|
| AAI143-S50 | 16-channel analog input module | Compact DIN-rail mount | ~0.3 |
| AAI543-S50 | 16-channel analog output module | Compact enclosure | ~0.4 |
| ADV151-P00 | Fast-response digital output module | Panel mount | ~0.35 |
| SDV144-S53 | 16-channel digital input module | Slim module | ~0.3 |
| PW402 | System power supply module | Mid-size rack mount | ~0.9 |
Q1: What is the primary role of the EC402-51?
A1: It connects the FCU to multiple Node Units over the ESB bus, ensuring fast and reliable communication within a DCS.
Q2: How many nodes can the EC402-51 support?
A2: Up to 13 Node Units can be connected to a single FCU via this module.
Q3: What communication speed does it support?
A3: The EC402-51 supports data transfer speeds up to 128 Mbps.
Q4: What power supply is required?
A4: It operates on a 24 V DC power supply via the system backplane.
Q5: What are the module’s dimensions and weight?
A5: The dimensions are 130 × 129.5 × 32.8 mm, and it weighs approximately 0.24 kg.
Q6: What diagnostic features does it have?
A6: The module includes LEDs that indicate status and faults to assist with system monitoring.
Q7: What operating temperatures does it support?
A7: It functions reliably between –10 °C and +55 °C.
Q8: Is the module suitable for harsh industrial environments?
A8: Yes, it is designed to operate under high humidity and temperature variations typical in industrial settings.
Q9: Can this module support bus redundancy?
A9: While the EC402-51 itself is designed for high node capacity, redundancy is typically handled by specific models like EC402-50 S1.
Q10: What types of systems are compatible with this module?
A10: It is compatible with Yokogawa’s CENTUM VP, CS 3000, and other DCS platforms.
Authenticity guarantee
All product specifications are original and authentic imported products. We have an annual sales volume of 300 million yuan, and we only produce original and authentic products. All customers who cooperate with us directly online can enjoy low discounts.
Free warehouse
We have a complete range of product models, 80% of conventional models are in stock, and we have established channels in Asia, Africa, North America, South America, and Europe, effectively shortening the order processing time and satisfying customers in a timely manner.
Technical Team
Fast delivery. Spot goods can be shipped on the same day, and the delivery time transaction is 20% faster than that of peers on average, with a delivery time accuracy rate of 99%.
Thoughtful after-sales service
24-hour after-sales service guarantee team, professional and standardized management service system.